Campbell Biology Chapter 31 (powell_h)
1) The hydrolytic digestion of which of the following should produce
monomers that are aminated (i.e., have an amine group attached)
molecules of β-glucose?
A) insect exoskeleton
B) plant cell walls
C) fungal
cell walls
D) Three of these responses are correct.
E) Two
of these responses are correct.
Answer: E
2) If all fungi in an environment that perform decomposition were to
suddenly die, then which group of organisms should benefit most, due
to the fact that their fungal competitors have been removed?
A)
plants
B) protists
C) prokaryotes
D) animals
E) mutualistic fungi
Answer: C
3) When a mycelium infiltrates an unexploited source of dead organic
matter, what are most likely to appear within the food source soon
thereafter?
A) fungal haustoria
B) soredia
C) fungal
enzymes
D) increased oxygen levels
E) larger bacterial populations
Answer: C
4) Which of the following is a characteristic of hyphate fungi (fungi
featuring hyphae)?
A) They acquire their nutrients by
phagocytosis.
B) Their body plan is a unicellular sphere.
C) Their cell walls consist mainly of cellulose microfibrils.
D) They are adapted for rapid directional growth to new food
sources.
E) They reproduce asexually by a process known as budding.
Answer: D
5) The functional significance of porous septa in certain fungal
hyphae is most similar to that represented by which pair of structures
in animal cells and plant cells, respectively?
A)
desmosomestonoplasts
B) gap junctionsplasmodesmata
C)
tight junctionsplastids
D) centriolesplastids
E)
flagellacentral vacuoles
Answer: B
6) What do fungi and arthropods have in common?
A) Both groups
are commonly coenocytic.
B) The haploid state is dominant in
both groups.
C) Both groups are predominantly heterotrophs that
ingest their food.
D) The protective coats of both groups are
made of chitin.
E) Both groups have cell walls.
Answer: D
7) In septate fungi, what structures allow cytoplasmic streaming to
distribute needed nutrients, synthesized compounds, and organelles
throughout the hyphae?
A) multiple chitinous layers in
cross-walls
B) pores in cross-walls
C) complex
microtubular cytoskeletons
D) two nuclei
E) tight
junctions that form in cross-walls between cells
Answer: B
8) What accounts most directly for the extremely fast growth of a
fungal mycelium?
A) rapid distribution of synthesized proteins
by cytoplasmic streaming
B) a long tubular body shape
C)
the readily available nutrients from their ingestive mode of nutrition
D) a dikaryotic condition that supplies greater amounts of
proteins and nutrients
Answer: A
9) The vegetative (nutritionally active) bodies of most fungi are
A) composed of hyphae.
B) referred to as a mycelium.
C) usually underground.
D) Three of these responses are
correct.
E) Two of these responses are correct.
Answer: D
10) Both fungus-farming ants and their fungi can synthesize the same
structural polysaccharide from the β-glucose. What is this
polysaccharide?
A) amylopectin
B) chitin
C)
cellulose
D) lignin
E) glycogen
Answer: B
11) Consider two hyphae having equal dimensions: one from a septate
species and the other from a coenocytic species. Compared with the
septate species, the coenocytic species should have
A) fewer
nuclei.
B) more pores.
C) less chitin.
D) less
cytoplasm.
E) reduced cytoplasmic streaming.
Answer: C
12) Immediately after karyogamy occurs, which term applies?
A)
plasmogamy
B) heterokaryotic
C) dikaryotic
D) diploid
Answer: D
13) Which description does not apply equally well to both sexual and
asexual spores?
A) have haploid nuclei
B) represent the
dispersal stage
C) are produced by meiosis
D) upon
germination, will subsequently undergo S phase and mitosis
Answer: C
14) Plasmogamy can directly result in which of the following?
1. cells with a single haploid nucleus
2. heterokaryotic
cells
3. dikaryotic cells
4. cells with two diploid nuclei
A) 1 or 2
B) 1 or 3
C) 2 or 3
D) 2 or 4
E) 3 or 4
Answer: C
15) After cytokinesis occurs in budding yeasts, the daughter cell has
a
A) smaller nucleus and more cytoplasm than the mother cell.
B) smaller nucleus and less cytoplasm than the mother cell.
C) larger nucleus and less cytoplasm than the mother cell.
D) similar nucleus and less cytoplasm than the mother cell.
Answer: D
16) In most fungi, karyogamy does not immediately follow plasmogamy,
which consequently
A) means that sexual reproduction can occur
in specialized structures.
B) results in multiple diploid nuclei
per cell.
C) allows fungi to reproduce asexually most of the
time.
D) results in heterokaryotic or dikaryotic cells.
E)
is strong support for the claim that fungi are not truly eukaryotic.
Answer: D
17) If all of their nuclei are equally active transcriptionally, then
the cells of both dikaryotic and heterokaryotic fungi, in terms of the
gene products they can make, are essentially
A) haploid.
B) diploid.
C) alloploid.
D) completely homozygous.
E) completely hemizygous.
Answer: B
18) Which process occurs in fungi and has the opposite effect on a
cell's chromosome number than does meiosis I?
A) mitosis
B) plasmogamy
C) crossing over
D) binary fission
E) karyogamy
Answer: E
19) Which of the following statements is true of deuteromycetes?
A) They are the second of five fungal phyla to have evolved.
B) They represent the phylum in which all the fungal components
of lichens are classified.
C) They are the group of fungi that
have, at present, no known sexual stage.
D) They are the group
that includes molds, yeasts, and lichens.
E) They include the
imperfect fungi that lack hyphae.
Answer: C
20) Fossil fungi date back to the origin and early evolution of
plants. What combination of environmental and morphological change is
similar in the evolution of both fungi and plants?
A) presence
of "coal forests" and change in mode of nutrition
B)
periods of drought and presence of filamentous body shape
C)
predominance in swamps and presence of cellulose in cell walls
D) colonization of land and loss of flagellated cells
E)
continental drift and mode of spore dispersal
Answer: D
21) Which of the following characteristics is shared by both chytrids
and other kinds of fungi?
A) presence of flagella
B)
zoospores
C) autotrophic mode of nutrition
D) cell walls
of cellulose
E) nucleotide sequences of several genes
Answer: E
22) The multicellular condition of animals and fungi seems to have
arisen
A) due to common ancestry.
B) by convergent
evolution.
C) by inheritance of acquired traits.
D) by
natural means, and is a homology.
E) by serial endosymbioses.
Answer: B
23) Asexual reproduction in yeasts occurs by budding. Due to unequal
cytokinesis, the "bud" cell receives less cytoplasm than the
parent cell. Which of the following should be true of the smaller cell
until it reaches the size of the larger cell?
A) It should
produce fewer fermentation products per unit time.
B) It should
produce ribosomal RNA at a slower rate.
C) It should be
transcriptionally less active.
D) It should have reduced
motility.
E) It should have a smaller nucleus.
Answer: A
24) The microsporidian, Brachiola gambiae, parasitizes the mosquito,
Anopheles gambiae. Adult female mosquitoes must take blood meals in
order for their eggs to develop, and it is while they take blood that
they transmit malarial parasites to humans. Male mosquitoes drink
flower nectar. If humans are to safely and effectively use Brachiola
gambiae as a biological control to reduce human deaths from malaria,
then how many of the following statements should be true?
1. Brachiola should kill the mosquitoes before the malarial
parasite they carry reaches maturity.
2. The microsporidian
should not be harmful to other insects.
3. Microsporidians
should infect mosquito larvae, rather than mosquito adults.
4.
The subsequent decline in anopheline mosquitoes should not
significantly disrupt human food resources or other food webs.
5. Brachiola must be harmful to male mosquitoes, but not to
female mosquitoes.
A) one statement only
B) two statements
C) three
statements
D) four statements
E) all five statements
Answer: C
25) Many infected animals are induced by the parasitic
microsporidians to develop huge cells, known as xenomas, which are
full of spores. Given their large size, what should be true of the
xenomas?
A) The parasite must endow the xenoma with some way to
overcome its unfavorable surface area-to-volume ratio.
B) The
xenoma must obtain mitochondria to survive.
C) The xenoma must
gain a cell wall; otherwise, it will lyse.
D) The xenoma acts as
a prison, of sorts, to keep the spores from escaping and infecting
other organisms.
Answer: A
26) What are the sporangia of the bread mold Rhizopus?
A)
asexual structures that produce haploid spores
B) asexual
structures that produce diploid spores
C) sexual structures that
produce haploid spores
D) sexual structures that produce diploid spores
Answer: A
27) Which of these paired fungal structures are structurally and
functionally most alike?
A) conidia and basidiocarps
B)
sporangia and hyphae
C) soredia and gills
D) haustoria and
arbuscules
E) zoospores and mycelia
Answer: D
28) You are given an organism to identify. It has a fruiting body
that contains many structures with eight haploid spores lined up in a
row. What kind of a fungus is this?
A) zygomycete
B)
ascomycete
C) deuteromycete
D) chytrid
E) basidiomycete
Answer: B
29) Which of the following has the least affiliation with all of the
others?
A) Glomeromycota
B) mycorrhizae
C) lichens
D) arbuscules
E) mutualistic fungi
Answer: C
30) Arrange the following from largest to smallest:
1. ascospore
2. ascocarp
3. ascomycete
4.
ascus
A) 3 → 4 → 2 → 1
B) 3 → 2 → 4 → 1
C) 3 → 4 → 1 → 2
D) 2 → 3 → 4 → 1
E) 2 → 4 → 1 → 3
Answer: B
31) Arrange the following from largest to smallest, assuming that
they all come from the same fungus.
1. basidiocarp
2. basidium
3. basidiospore
4.
mycelium
5. gill
A) 4 → 5 → 1→ 2 → 3
B) 5 → 1 → 4 → 2 → 3
C) 5 → 1 →
4 → 3 → 2
D) 5 → 1 → 3 → 2 → 4
E) 4 → 1 → 5 → 2 → 3
Answer: E
32) Among sac fungi, which of these correctly distinguishes
ascospores from conidia?
A) Ascospores are diploid, whereas
conidia are haploid.
B) Ascospores are produced only by meiosis,
whereas conidia are produced only by mitosis.
C) Ascospores have
undergone genetic recombination during their production, whereas
conidia have not.
D) Ascospores are larger, whereas conidia are
smaller.
E) Ascospores will germinate into haploid hyphae,
whereas conidia will germinate into diploid hyphae.
Answer: C
33) A fungal spore germinates, giving rise to a mycelium that grows
outward into the soil surrounding the site where the spore originally
landed. Which of the following accounts for the fungal movement, as
described here?
A) karyogamy
B) mycelial flagella
C)
alternation of generations
D) breezes distributing spores
E) cytoplasmic streaming in hyphae
Answer: E
34) In what structures do both Penicillium and Aspergillus produce
asexual spores?
A) asci
B) zygosporangia
C) rhizoids
D) gametangia
E) conidiophores
Answer: E
35) Chemicals, secreted by soil fungi, that inhibit the growth of
bacteria are known as
A) antibodies.
B) aflatoxins.
C) hallucinogens.
D) antigens.
E) antibiotics.
Answer: E
36) Lichens are symbiotic associations of fungi and
A) mosses.
B) cyanobacteria.
C) green algae.
D) Three of these
responses are correct.
E) Two of these responses are correct.
Answer: E
37) In both lichens and mycorrhizae, what does the fungal partner
provide to its photosynthetic partner?
A) carbohydrates
B)
fixed nitrogen
C) antibiotics
D) water and minerals
E) protection from harmful UV
Answer: D
38) Which of the following best describes the physical relationship
of the partners involved in lichens?
A) Fungal cells are
enclosed within algal cells.
B) Lichen cells are enclosed within
fungal cells.
C) Photosynthetic cells are surrounded by fungal
hyphae.
D) The fungi grow on rocks and trees and are covered by
algae.
E) Algal cells and fungal cells mix together without any
apparent structure.
Answer: C
39) If haustoria from the fungal partner were to appear within the
photosynthetic partner of a lichen, and if the growth rate of the
photosynthetic partner consequently slowed substantially, then this
would support the claim that
A) algae and cyanobacteria are
autotrophic.
B) lichens are not purely mutualistic
relationships.
C) algae require maximal contact with the fungal
partner in order to grow at optimal rates.
D) fungi get all of
the nutrition they need via the "leakiness" of
photosynthetic partners.
E) soredia are asexual reproductive
structures combining both the fungal and photosynthetic partners.
Answer: B
40) When pathogenic fungi are found growing on the roots of grape
vines, grape farmers sometimes respond by covering the ground around
their vines with plastic sheeting and pumping a gaseous fungicide into
the soil. The most important concern of grape farmers who engage in
this practice should be that the
A) fungicide might also kill
the native yeasts residing on the surfaces of the grapes.
B)
lichens growing on the vines' branches are not harmed.
C)
fungicide might also kill mycorrhizae.
D) sheeting is
transparent so that photosynthesis can continue.
Answer: C
41) Which of the following terms refers to symbiotic relationships
that involve fungi living between the cells in plant leaves?
A)
pathogens
B) endosymbioses
C) endophytes
D) lichens
E) mycorrhizae
Answer: C
42) If Penicillium typically secretes penicillin without disturbing
the lichen relationship in which it is engaged, then what must have
been true about its partner?
A) It should have lacked
peptidoglycan in its cell wall.
B) It was probably a red alga.
C) It was probably a member of the domain Bacteria.
D) It
was probably a heterotrophic prokaryote.
E) It was probably
infected by bacteriophage.
Answer: A
43) Sexual reproduction has never been observed among the fungi that
produce the blue-green marbling of blue cheeses. What is true of these
fungi and others that do not have a sexual stage?
A) They are
currently classified among the ascomycetes.
B) They do not form
heterokaryons.
C) Their spores are probably produced by mitosis.
D) Three of these responses are correct.
E) Two of these
responses are correct.
Answer: C
44) Both fungus-derived antibiotics and hallucinogens used by humans
probably evolved in fungi as a means to
A) reduce competition
for nutrients.
B) help humanity survive.
C) promote their
ingestion of foodstuffs.
D) eliminate other fungi.
E)
discourage animal predators.
Answer: A
45) A billionaire buys a sterile volcanic island that recently
emerged from the sea. To speed the arrival of conditions necessary for
plant growth, the billionaire might be advised to aerially sow what
over the island?
A) basidiospores
B) spores of
ectomycorrhizae
C) soredia
D) yeasts
E) leaves (as
food for fungus-farming ants)
Answer: C
46) Mycorrhizae are to the roots of vascular plants as endophytes are
to vascular plants'
A) leaf mesophyll.
B) stem apical
meristems.
C) root apical meristems
D) xylem.
E)
waxy cuticle.
Answer: A
47) Which of the following conditions is caused by a fungus that is
accidentally consumed along with rye flour?
A) ergotism
B)
athlete's foot
C) ringworm
D) candidiasis (Candida yeast
infection)
E) coccidioidomycosis
Answer: A
48) Orchid seeds are tiny, with virtually no endosperm and with
miniscule cotyledons. If such seeds are deposited in a dark, moist
environment, then which of the following represents the most likely
means by which fungi might assist in seed germination, given what the
seeds lack?
A) by transferring some chloroplasts to the embryo
in each seed
B) by providing the seeds with water and minerals
C) by providing the embryos with some of the organic nutrients
they have absorbed
D) by strengthening the seed coat that
surrounds each seed
Answer: C
49) Which tree depicts the microsporidians as a sister group of the
ascomycetes?
A) I
B) II
C) III
D) IV
Answer: A
50) Which tree depicts the closest relationship between zygomycetes
and chytrids?
A) I
B) II
C) III
D) IV
Answer: C
51) Which tree depicts the microsporidians as a sister group of the
fungi, rather than as a fungus?
A) I
B) II
C) III
D) IV
Answer: D
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
52) What is the most probable location of the oldest portion of
this mycelium?
A) A
B) B
C) C
D) D
Answer: C
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
53) Which location is nearest to basidiocarps?
A) A
B) B
C) C
D) D
Answer: A
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
54) At which location is the mycelium currently absorbing the
most nutrients per unit surface area, per unit time?
A) A
B) B
C) C
D) D
Answer: A
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
55) At which location should one find the lowest concentration
of fungal enzymes, assuming that the enzymes do not diffuse far from
their source, and that no other fungi are present in this habitat?
A) A
B) B
C) C
D) D
Answer: D
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
56) Assume that all four locations are 0.5 m above the surface.
On a breezy day with prevailing winds blowing from left to right,
where should one expect to find the highest concentration of free
basidiospores in an air sample?
A) A
B) B
C) C
D) D
Answer: D
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
57) In which of the following human mycoses should one expect to
find a growth pattern most similar to that of the mycelium that
produced the fairy ring?
A) skin mycoses
B)
coccidiomycosis (lung infection)
C) systemic (bloodborne)
Candida infection
D) Sporothrix infection of lymphatic vessels
E) Tinea tonsurans infection limited to interior of hair shafts
Answer: A
The following figure depicts the outline of a large fairy ring that
has appeared overnight in an open meadow, as viewed from above. The
fairy ring represents the furthest advance of this mycelium through
the soil. Locations AD are all 0.5 meters below the soil surface.
Responses may be used once, more than once, or not at all.
58) If the fungus that produced the fairy ring can also produce
arbuscules, then which of the following is most likely to be buried at
location "C"?
A) septic tank
B) tree stump
C) deceased animal
D) fire pit
E) cement-capped well
Answer: B
Diploid nuclei of the ascomycete, Neurospora crassa, contain 14
chromosomes. A single diploid cell in an ascus will undergo one round
of meiosis, followed in each of the daughter cells by one round of
mitosis, producing a total of eight ascospores.
59) If a single, diploid G₂ nucleus in an ascus contains 400
nanograms (ng) of DNA, then a single ascospore nucleus of this species
should contain how much DNA (ng), carried on how many chromosomes?
A) 100, carried on 7 chromosomes
B) 100, carried on 14
chromosomes
C) 200, carried on 7 chromosomes
D) 200,
carried on 14 chromosomes
E) 400, carried on 14 chromosomes
Answer: A
Diploid nuclei of the ascomycete, Neurospora crassa, contain 14
chromosomes. A single diploid cell in an ascus will undergo one round
of meiosis, followed in each of the daughter cells by one round of
mitosis, producing a total of eight ascospores.
60) What is the ploidy of a single mature ascospore?
A)
monoploid
B) diploid
C) triploid
D) tetraploid
E) polyploid
Answer: A
Diploid nuclei of the ascomycete, Neurospora crassa, contain 14
chromosomes. A single diploid cell in an ascus will undergo one round
of meiosis, followed in each of the daughter cells by one round of
mitosis, producing a total of eight ascospores.
61) Each of the eight ascospores present at the end of mitosis
has the same chromosome number and DNA content (ng) as each of the
four cells at the end of meiosis. What must have occurred in each
spore between the round of meiosis and the round of mitosis?
A)
double fertilization
B) crossing over
C) nondisjunction
D) autopolyploidy
E) S phase
Answer: E
Unicellular yeasts can be represented as spheres, whereas filamentous
hyphae more closely resemble cylinders. As these two geometric figures
increase in size, their surface area-to-volume ratios change. The
following tables demonstrate how this ratio changes, first for
spheres, and second for cylinders. For the cylinder, girth (i.e.,
radius, r) will remain constant, whereas length, L, will increase.
Note the formulas below the respective tables.
62) As a direct result of increasing surface area in both yeasts
and filamentous hyphae, which cell structures/materials must also
increase?
1. amount of chitin
2. number of nuclei
3. amount of
plasma membrane
4. number of mitochondria
5. amount of
peptidoglycan
A) 1 only
B) 1 and 3
C) 2 and 3
D) 2 and 4
E) 1, 3, and 5
Answer: B
Unicellular yeasts can be represented as spheres, whereas filamentous
hyphae more closely resemble cylinders. As these two geometric figures
increase in size, their surface area-to-volume ratios change. The
following tables demonstrate how this ratio changes, first for
spheres, and second for cylinders. For the cylinder, girth (i.e.,
radius, r) will remain constant, whereas length, L, will increase.
Note the formulas below the respective tables.
63) Which statement is a correct interpretation of the data in
the previous tables?
A) As a sphere gets bigger, its surface
area and volume increase at about the same pace.
B) As a
cylinder gets bigger, its surface area increases at a greater pace
than does its volume.
C) As a cylinder gets bigger, its volume
increases at about the same pace at which the volume of a sphere
increases.
D) As spheres and cylinders get bigger, the surface
area of a cylinder increases at a faster pace than does the surface
area of a sphere.
Answer: B
64) Both axes of the graph are linear. Thus, the shape of the line
plotted on this graph most accurately depicts the
A) volume of a
sphere as the radius, r, increases.
B) surface area of a sphere
as the radius, r, increases.
C) volume of a cylinder as length,
L, increases.
D) surface area of a cylinder as length, L, increases.
Answer: C
65) Surface area represents the area available for exchange with the
environment, whereas volume represents the cytoplasm which requires
nutrients and from which waste products (usually toxic) must be
removed. Which of the following should provide the most favorable
conditions for effective exchange?
A) a smaller unicellular
yeast
B) a larger unicellular yeast
C) a shorter
filamentous hypha
D) a longer filamentous hypha
Answer: D
66) Some fungi can exist either as unicellular yeasts or as
filamentous hyphae. Which of these forms would be most favorable in an
environment where nutrients are limited?
A) a smaller
unicellular yeast
B) a larger unicellular yeast
C) a
shorter filamentous hypha
D) a longer filamentous hypha
Answer: D
Recent genetic studies of the structure of microsporidian genomes, as
well as the sequences of their tubulin genes and the gene for RNA
polymerase II, indicate that microsporidians are closely related to
the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and
mitochondria (although they do have degenerate mitochondria, called
mitosomes). They have the smallest genome of any eukaryote, and it is
a genome that changes quickly. The genome is contained within two
haploid nuclei. All microsporidians are obligate intracellular
parasites. They use a unique organelle called a polar filament to gain
access to the cells of their hosts. One species causes chronic
diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the
mosquito that transmits a fatal form of malaria to humans.
67) Given the eukaryotic structures they lack, it should be
expected that microsporidians also lack
A) the "9 + 2
pattern" of microtubules.
B) chitin.
C) lysosomes.
D) nuclei.
E) centrosomes.
Answer: A
Recent genetic studies of the structure of microsporidian genomes, as
well as the sequences of their tubulin genes and the gene for RNA
polymerase II, indicate that microsporidians are closely related to
the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and
mitochondria (although they do have degenerate mitochondria, called
mitosomes). They have the smallest genome of any eukaryote, and it is
a genome that changes quickly. The genome is contained within two
haploid nuclei. All microsporidians are obligate intracellular
parasites. They use a unique organelle called a polar filament to gain
access to the cells of their hosts. One species causes chronic
diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the
mosquito that transmits a fatal form of malaria to humans.
68) The lifestyle of microsporidians is most similar to that of
A) scavengers.
B) viruses.
C) free-living yeasts.
D) ectoparasites.
Answer: B
Recent genetic studies of the structure of microsporidian genomes, as
well as the sequences of their tubulin genes and the gene for RNA
polymerase II, indicate that microsporidians are closely related to
the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and
mitochondria (although they do have degenerate mitochondria, called
mitosomes). They have the smallest genome of any eukaryote, and it is
a genome that changes quickly. The genome is contained within two
haploid nuclei. All microsporidians are obligate intracellular
parasites. They use a unique organelle called a polar filament to gain
access to the cells of their hosts. One species causes chronic
diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the
mosquito that transmits a fatal form of malaria to humans.
69) Which of the following microsporidian features are shared
with many other fungi?
1. chitinous cell wall
2. two haploid nuclei per cell
3. polar filament
4. chemoheterotrophy
A) 1 and 2
B) 1 and 3
C) 1 and 4
D) 1, 2, and
4
E) 2, 3, and 4
Answer: D
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
70) Apart from direct amphibian-to-amphibian contact, what is
the most likely means by which the zoospores spread from one
free-living amphibian to another?
A) by wind-blown spores
B) by flagella
C) by cilia
D) by pseudopods
E)
by hyphae
Answer: B
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
71) The chytrid sporangia reside within the amphibian epidermal
cells. Consequently, which term(s) apply to Bd?
1. ectosymbionts
2. parasites
3. commensals
4.
pathogens
5. endosymbionts
A) 1 and 2
B) 1 and 3
C) 2 and 4
D) 2, 3, and
5
E) 2, 4, and 5
Answer: E
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
72) Which of the following are protists, the organisms thought
to share the closest ancestor with the chytrids?
A) nucleariids
B) choanoflagellates
C) zygomycetes
D) algae
E) diplomonads
Answer: A
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
73) Sexual reproduction has not been observed in Bd. A Bd
sporangium initially contains a single, haploid cell. Which of the
following processes must be involved in generating the multiple
zoospores eventually produced by each sporangium?
1. S phase
2. cytokinesis
3. mitosis
4.
meiosis
A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and
3
E) 1, 2, and 4
Answer: D
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
74) Sexual reproduction has not been observed in Bd. If its
morphology and genetics did not identify it as a chytridiomycete, then
to which fungal group would Bd be assigned?
A) ascomycetes
B) zygomycetes
C) glomeromycetes
D) basidiomycetes
E) deuteromycetes
Answer: E
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
75) If infection primarily involves the outermost layers of
adult amphibian skin, and if the chytrids use the skin as their sole
source of nutrition, then which term best applies to the chytrids?
A) anaerobic chemoautotroph
B) aerobic chemoautotroph
C) anaerobic chemoheterotroph
D) aerobic chemoheterotroph
Answer: D
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
76) If Bd cannot grow properly at temperatures above 28°C
(82°F), then, assuming the amphibians can survive, in which time or
place should the chytrid infection proceed most rapidly?
1. cooler months
2. warmer months
3. lower altitudes
4. higher altitudes
A) 1 or 3
B) 1 or 4
C) 2 or 3
D) 2 or 4
Answer: B
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
77) What makes it risky to rely on the presence of chitin in
adult amphibian skin as the sole positive test for the presence of
chytrids?
A) Other mycoses may be in progress in the same
amphibian simultaneously.
B) The amphibian may harbor arthropod
ectoparasites simultaneously.
C) Bacterial infections may be
simultaneously underway in the amphibian.
D) Three of the
responses above are correct.
E) Two of the responses above are correct.
Answer: E
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
78) The fact that infection by Bd causes lethargy in many
infected amphibians can have what effect on efforts to accurately
census the numbers of dead or dying amphibians at a particular time,
in a particular habitat?
A) It can cause underestimation, due to
infected amphibians preferring to seek out refuges relative to
uninfected amphibians.
B) It can cause underestimation, due to
increased predation on, and removal of, infected amphibians relative
to uninfected amphibians.
C) It can cause overestimation,
because infected frogs should be more readily observable to human
census-takers than should uninfected amphibians.
D) All three of
the above statements are plausible.
E) Two of the above
statements are plausible.
Answer: E
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
79) When adult amphibian skin harbors populations of the
bacterium, Janthinobacterium lividum (Jl), chytrid infection seems to
be inhibited. Which of the following represents the best experimental
design for conclusively determining whether this inhibition is real?
A) Inoculate uninfected amphibians with Jl, and determine
whether the amphibians continue to remain uninfected by chytrids.
B) Inoculate infected amphibians with Jl, and determine whether
the amphibians recover from infection by chytrids.
C) Take
infected amphibians and assign them to two populations. Leave one
population alone; inoculate the other with Jl. Measure the rate at
which infection proceeds in both populations.
D) Take infected
amphibians and assign them to two populations. Inoculate one
population with a high dose of Jl; inoculate the other with a low dose
of Jl. Measure the survival frequency in both populations.
Answer: C
For several decades now, amphibian species worldwide have been in
decline. A significant proportion of the decline seems to be due to
the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Chytrid sporangia reside within the epidermal cells of infected
animals, animals that consequently show areas of sloughed skin. They
can also be lethargic, which is expressed through failure to hide and
failure to flee. The infection cycle typically takes four to five
days, at the end of which zoospores are released from sporangia into
the environment. In some amphibian species, mortality rates approach
100%; other species seem able to survive the infection.
80) A researcher took water in which a Jl population had been
thriving, filtered the water to remove all bacterial cells, and then
applied the water to the skins of adult amphibians to see if there
would subsequently be a reduced infection rate by Bd when frog skins
were inoculated with Bd. For which of the following hypotheses is the
procedure described a potential test?
A) the hypothesis that a
toxin secreted by Jl cells kills Bd cells when both are present
together on frog skin
B) the hypothesis that Jl cells infect and
kill Bd cells when both are present together on frog skin
C) the
hypothesis that Jl outcompetes Bd when both are present together on a
frog's skin
D) the hypothesis that the presence of Jl on frog
skin causes a skin reaction that prevents attachment by Bd cells
Answer: A
Rose-picker's disease is caused by the yeast, Sporothrix schenkii.
The yeast grows on the exteriors of rose-bush thorns. If a human gets
pricked by such a thorn, the yeasts can be introduced under the skin.
The yeasts then assume a hyphal morphology and grow along the
interiors of lymphatic vessels until they reach a lymph node. This
often results in the accumulation of pus in the lymph node, which
subsequently ulcerates through the skin surface and then drains.
81) The answer to which of these questions would be of most
assistance to one who is attempting to assign the genus Sporothrix to
the correct fungal phylum?
A) Do these yeasts perform
fermentation while growing on the rose-bush thorns, or do they wait
until inside a human host?
B) Does S. schenkii rely on animal
infection to complete some part of its life cycle, or is the infection
merely opportunistic?
C) Are the hyphae in lymphatic vessels
septate, or are they coenocytic?
D) Is S. schenkii best
described as a decomposer, parasite, pathogen, or mutualist of humans?
E) Being a yeast, does S. schenkii perform the process of budding?
Answer: B
Rose-picker's disease is caused by the yeast, Sporothrix schenkii.
The yeast grows on the exteriors of rose-bush thorns. If a human gets
pricked by such a thorn, the yeasts can be introduced under the skin.
The yeasts then assume a hyphal morphology and grow along the
interiors of lymphatic vessels until they reach a lymph node. This
often results in the accumulation of pus in the lymph node, which
subsequently ulcerates through the skin surface and then drains.
82) Say S. schenkii had initially been classified as a
deuteromycete. Asci were later discovered in the pus that oozed from
an ulcerated lymph node, and the spores therein germinated, giving
rise to S. schenkii yeasts. Which two of these are conclusions that
make sense on the basis of this information?
1. S. schenkii produces asexual spores within lymph nodes.
2. S. schenkii should be reclassified.
3. S. schenkii
continues to have no known sexual stage.
4. The hyphae growing
in lymphatic vessels probably belonged to a different fungal species.
5. S. schenkii yeasts belonging to two different mating strains
were introduced by the same thorn prick.
A) 1 and 3
B) 1 and 5
C) 2 and 3
D) 2 and 5
E) 4 and 5
Answer: D
Rose-picker's disease is caused by the yeast, Sporothrix schenkii.
The yeast grows on the exteriors of rose-bush thorns. If a human gets
pricked by such a thorn, the yeasts can be introduced under the skin.
The yeasts then assume a hyphal morphology and grow along the
interiors of lymphatic vessels until they reach a lymph node. This
often results in the accumulation of pus in the lymph node, which
subsequently ulcerates through the skin surface and then drains.
83) Humans have immune systems in which lymph nodes are
important, because many phagocytes and lymphocytes reside there. Given
that a successful infection by S. schenkii damages lymph nodes
themselves, which of the following is most probable?
A) The
hyphae secrete antibiotics, which increases the ability of the
infected human to tolerate the fungus.
B) Their conversion from
yeast to hyphal morphology allows such fast growth that the body's
defenses are at least temporarily overwhelmed.
C) Defensive
cells of humans cannot detect foreign cells that are covered with cell
walls composed of cellulose.
D) Given that most fungal pathogens
attack plants, human defenses are simply not adapted to seek out and
destroy fungi.
E) Given that most fungal pathogens of humans
infect only the skin, human defenses are not adapted to seek out and
destroy systemic fungal infections.
Answer: B
84) All fungi share which of the following characteristics?
A)
symbiotic
B) heterotrophic
C) flagellated
D)
pathogenic
E) act as decomposers
Answer: B
85) Which feature seen in chytrids supports the hypothesis that they
diverged earliest in fungal evolution?
A) the absence of chitin
within the cell wall
B) coenocytic hyphae
C) flagellated
spores
D) formation of resistant zygosporangia
E)
parasitic lifestyle
Answer: C
86) Which of the following cells or structures are associated with
asexual reproduction in fungi?
A) ascospores
B)
basidiospores
C) zygosporangia
D) conidiophores
E) ascocarps
Answer: D
87) The photosynthetic symbiont of a lichen is often
A) a moss.
B) a green alga.
C) a brown alga.
D) an ascomycete.
E) a small vascular plant.
Answer: B
88) Among the organisms listed here, which are thought to be the
closest relatives of fungi?
A) animals
B) vascular plants
C) mosses
D) brown algae
E) slime molds
Answer: A
89) The adaptive advantage associated with the filamentous nature of
fungal mycelia is primarily related to
A) the ability to form
haustoria and parasitize other organisms.
B) avoiding sexual
reproduction until the environment changes.
C) the potential to
inhabit almost all terrestrial habitats.
D) the increased
probability of contact between different mating types.
E) an
extensive surface area well suited for invasive growth and absorptive nutrition.
Answer: E